Parents are being warned to pay attention to the app Musical.ly, which has more than 200 million users. The app, which can be used on cellphones, is designed to create and share videos of lip-syncing, which seems harmless enough. However, if certain words are typed into the app, disturbing and inappropriate videos could appear, KTVB reported.

Reports of videos that showed children stripping and flashing the camera have surfaced, along with other users “liking” the actions to egg on the participants. Code words are constantly changing in order to skirt the app’s moderators, KTVB reported.

Videos featuring anorexia, suicide and self-harm also have surfaced when certain words are typed into the app, KTVB reported.

David Gomez, a school resource officer in Meridian, Idaho, who teaches an internet safety class, said it's vitally important that parents not only know what their kids are doing online, but to also tell their kids they are watching.

"As a parent, if you show your kid that you are checking on them and that you do care and that you're going to be watching out for their best interest, a lot of times that will help shape their decisions when you're not around," Gomez told KTVB.

Parents can use parental controls to block the Musical.ly app altogether, the station reported.